RF receivers with increased coverage of the RF spectrum are necessary in order to meet ever increasing mission capabilities. Known RF receiver systems use a large number of pre-selection filters and ultra-wideband local oscillators (LO) to achieve a wide RF spectrum coverage. Current approaches also rely on a Zero-IF receiver architecture with a VCO/PLL to cover the larger RF spectrum range at the expense of limited IBW (<200 MHz). Multiple LO tones separated by the IBW to achieve wideband coverage are required
Frequency conversion through a mixer is limited in spectrum coverage due to balun designs. Either the RF/LO ports are limited or the IF port is limited in BW as the IF BW of track-and-hold amplifiers is broadband and covers up-to the 1st Nyquist null frequency.
Other known approaches utilize multiple Nyquist zones folding to cover the desired RF spectrum but suffer from low sensitivity due to the large number of aliases and require signal processing to determine the actual frequency of the signals of interest.
Complex LO generation and the large number of RF pre-selection filters, however, require a large amount of space, weight and power to accommodate them in a design.
What is needed is a receiver architecture that does not need large filter banks and avoids complex LO generation but still obtains ultra-wideband RF spectrum coverage.